| U Geminorum stars | Etoiles U Geminorum |
| U magnitude | Magnitude U |
| U Nu | U Nu |
| U Thant | U Thant |
| U Thant Island | U Thant Island |
| U Turn | U Turn |
| U-boat | U-boot |
| U-bolt | Arc |
| U-Foes | U-Foes |
| U-Roy | U Roy |
| U-shaped valley | Vallée glaciaire |
| U-Tapao | U-Tapao |
| U-turn | revirement |
| U.S. | États-Unis |
| U.S. of A. | États-Unis |
| U.S.A. | États-Unis |
| U.S.S.R. | U.R.S.S. |
| Ua Pu | Ua Pou |
| Uaboe | Uaboe |
| UAC TurboTrain | Train Turbo |
| UAE | EAU |
| UAG Tecos | UAG Tecos |
| UANL Tigres | Tigres UANL |
| UAO-DLR Asteroid Survey | Uppsala-DLR Asteroid Survey |
| Uaxactun | Uaxactun |
| UAZ | UAZ |
| UB Conquense | Unión Balompédica Conquense |
| UB-Barça | UB-FC Barcelone |
| Ubaldo Fillol | Ubaldo Fillol |
| Ubangi | Ubangi |
| Ubangi River | Ubangi |
| Ubayd Allah al-Mahdi Billah | Ubayd Allah al-Mahdi |
| Ubayd Zakani | Obeid Zakani |
| Ube | Ube |
| Ubenide | Ubenide |
| uber- | mega- |
| Uberaba | Uberaba |
| Ubermensch | Superman |
| Ubii | Ubiens |
| Ubinas | Ubinas |
| ubiquitous | doué d'ubiquité |
| Ubiquitous computing | Informatique ubiquitaire |
| ubiquity | ubiquité |
| Ubisoft | Ubisoft |
| Ubon Ratchathani | Ubon Ratchathani |
| Ubon Ratchathani Province | Province de Ubon Ratchathani |
| UBS AG | UBS |
| UBU | Ubu |
| Ubu Roi | Ubu Roi |
| Ubuntu Lite | Ubuntu Lite |
| UBV photometry | Photometrie UBV |
| UBVGRI photometry | Photometrie UBVGRI |
| UBVRI photometry | Photometrie UBVRI |
| UBVRIJKL photometry | Photometrie UBVRIJKL |
| Ubykh language | Oubykh |
| Ucayali River | Río Ucayali |
| UCB | UCB Pharma |
| UCBV photometry | Photometrie UCBV |
| Uccle | Uccle |
| UCF Knights football | UCF Golden Knights |
| Uchi-deshi | Uchi deshi |
| Uchimura Kanzō | Kanzō Uchimura |
| Uchuu Keiji Gavan | X-Or |
| Uchuu Keiji Shaider | Capitaine Sheider |
| Uchuu Keiji Sharivan | Sharivan |
| UCI Continental Circuits | Circuits continentaux de cyclisme |
| UCI ProTour | UCI ProTour |
| UCI Road World Cup | Coupe du monde de cyclisme sur route |
